Plate type heat exchangers



April 30, 1968 A. G. BUTT 3,380,517

PLATE TYPE HEAT EXCHANGERS Filed Sept. 26, 1966 5 Sheets-Sheet 1 2 FIG! 2 5 I s j I 3 L ii FIG. 3

I8 4a 141; 46 so 24 INVENTOR.

ALAN G. BUTT ATTORNEY April 30, 1968 A. G.- BUTT 3,380,517

PLATE TYPE HEAT EXCHANGERS Filed Sept. 26, 1966 3 Sheets-Sheet 2 FIG. 4

FIG. 6

m'vli/v'roR. ALAN G. BUTT BY w o AT TORNE Y April 0, 1968 A. G. BUTT PLATE TYPE HEAT EXCHANGERS 5 Sheets-Sheet 5 Filed Sept. 26, 1966 INVENTOR.

ALAN G. BUTT BY dJ%&/

- ATTORNEY United States Patent 3,380,517 PLATE TYPE HEAT EXCHANGERS Alan G. Butt, La Crosse, Wis., assignor to The Trane Company, La Crosse, Wis., a corporation of Wisconsin Filed Sept. 26, 1966, Ser. No. 582,155 14 Claims. (Cl. 165166) This invention relates to brazed plate type heat exchangers and more particularly to structure for providing fluid communication to the passages of the heat exchanger intermediate the inlet and outlet thereof.

In fluid processes it often is required that a fluid stream be divided into two or more separate streams which may be conducted in separate flow paths. In some circumstances it is desirable to make this division within heat exchange passages whereby one portion of the fluid stream may pass entirely through the passages while another por tion of the fluid stream may pass only part way through these passages.

The instant invention permits division of the fluid stream within plate type heat exchangers. With the structure herein disclosed this division may be accomplished uniformly and without disruption to the flow of fluid passing all the way through the passages.

It is thus an object of this invention to provide a plate type heat exchanger with means for uniformly communieating with certain of the passages intermediate the entering and leaving ends thereof.

It is a further object of this invention to provide a brazed plate type heat exchanger with means to uniformly bleed off a portion of the fluid flowing through a plate type heat exchange passage at a point intermediate to the entering and leaving ends thereof without disturbing the uniform fluid distribution across the width of the passage.

It is another object of the invention to provide a brazed plate type heat exchanger having means for introducing or withdrawing fluid intermediate the inlet and outlets of certain of the passages wherein structural continuity is maintained throughout via corrugated fin packing.

This invention involves a plate type heat exchanger having a plurality of separator plates of generally similar configuration spaced in superposed substantially parallel relationship along a first axis; means sealingly connecting adjacent separator plates along the margins thereof thereby defining fluid passages between said separator plates; means for conducting heat exchange fluid from one end to the other end of each of said passages in a direction generally parallel to a second axis extending parallel to said separator plates; a baflle plate in one of said passages intermediate the ends thereof interposed in spaced substantially parallel relationship to said separator plates that define said one passage; a first heat exchange fin packing member disposed in said one passage at one face of said baffle plate and oriented to conduct heat exchange fluid in a direction generally parallel to said second axis; a second heat exchange fin packing member disposed in said one passage at the other face of said baflle plate oriented to conduct heat exchange fluid in a direction generally parallel to a third axis extending perpendicular to said first axis and transverse to said second axis; a third heat exchange fin packing member disposed in said one passage downstream of said baflle plate and having fins extending from one separator plate to the other one of said separator plates defining said one passage; and a port extending through said sealing means adjacent to and communicating with said second heat exchange fin member.

Other objects and advantages will become apparent as this specification proceeds to describe this invention with reference to the accompanying drawings in which:

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FIGURE 1 is a side view of a plate type heat exchanger incorporating the invention;

FIGURE 2 is a plan view of the heat exchanger as indicated by line 22 in FIGURE 1;

FIGURE 3 is a section of the heat exchanger taken at line 3-3 of FIGURE 1;

FIGURE 4 is a section of the heat exchanger taken at line 4-4 of FIGURE 1;

FIGURE 5 is a section of the heat exchanger taken at line 55 of FIGURE 1;

FIGURE 6 is a section through the heat exchanger bleed header taken at line 66 of FIGURE 2;

FIGURE 7 is an exploded perspective of a passage of the heat exchanger showing detail structure for uniformly bleeding off or introducing a portion of the fluid passing through the passage;

FIGURE 8 is an enlarged perspective showing a plain or impervious corrugated fin packing member utilized in the heat exchanger; and

FIGURE 9 is an enlarged perspective showing a perforated corrugated fin packing member utilized in the heat exchanger.

Now with reference to the drawings, it will be seen that heat exchanger 10 has a plurality of elongated rectangular metallic separator plates 12 spaced in superposed parallel relationship along a first axis. Plates 12 are connected at their margins as by a plurality of closing bars 14 sealingly brazed to adjacent separator plates thereby defining flat fluid conducting passages therebetween for passage of heat exchange fluids. Certain passages 16 of said fluid conducting passages have a common inlet header 18 and a common outlet header 20 at opposite ends of the heat exchanger for passing a first heat exchange fluid therethrough in a direction parallel to a second axis extending normal to said first mentioned axis. Other passages 22 of said fluid conducting passages have a common inlet header 24 and a common outlet header 26 at opposite ends of the heat exchanger for passing a second heat exchange fluid therethrough in a direction parallel to said second axis in counterflow relationship with said first heat exchange fluid. A fifth header 28 overlies a portion of a side of heat exchanger 10 which is formed in part by closing bars 14 in an area intermediate the ends of the heat exchanger.

Now with particular reference to FIGURE 5 it will be seen that passages 16 are filled with corrugated fin packing members including a centrally disposed elongated rectangular section 30, a trapezoidal distributor section 32 adjacent each end of section 30, and a triangular distributor section 34 interposed between each of sections 32 and headers 18 and 20. The perforated fin packing 36 forming sections 30 and 32 may be of the serrated type as shown in greater detail in FIGURE 9. Fin packing 36 i comprised of a layer of corrugated sheet metal such as aluminum wherein each corrugation is provided with a series of offset portions 38 producing a series of slits 40 therein. The particulars of this fin material are fully described in US. Patent No. 3,016,921. Fin packing 44 forming sections 34 may simply be an imperforate corrugated metallic sheet as illustrated in FIG- URE 8.

The details of passages 22 are illustrated in the sectional views of FIGURES 3 and 4 and the exploded perspective of FIGURE 7. Thus it will be seen that passages 22 are filled with corrugated fin packing members including two rectangular sections 46 spaced along the aforementioned second axis; a trapezoidal distributor section 48 adjacent each end of passage 22, and a triangular distributor section 50 interposed between each of sections 32 and headers 24 and 26. Distributor sections 48 and 50 are similar to distributor sections 32 and 34, respectively.

Similarly, section 46 is constructed of the same material as that of section 30, i.e. a perforated corrugated sheet such as illustrated in FIGURE 9.

It will be noted that in both passages 16 and 22 the aforementioned rectangular and triangular sections of corrugated fin packing are oriented with the crests and troughs thereof extending parallel to the aforementioned second axis for fluid flow in that direction while the trapezoidal sections of corrugated fin packing are oriented with the crests and troughs thereof extending obliquely to said second axis to permit uniform distribution or collection of fluid to or from the triangular sections. Thus the triangular and trapezoidal sections serve to establish uniform fluid distribution across the width of the passages. Each of the fin sections described thu far are of sutficient thickness to abut the separator plates defining the passages in which they are installed.

Having established a uniform fluid distribution across the width of passages 22 it is of utmost importance that such uniform distribution be maintained throughout the heat exchange passage to achieve eflicient heat transfer between passages 16 and 22. According to this invention there is provided, in each of passages 22 in the space between fin packing sections 46, means for withdrawing a portion of the heat exchange fluid without disturbing the uniformity of fluid distribution within passage 22.

Accordingly each of passages 22 has a rectangular baflle plate 52 disposed in the space between fin sections 46 positioned in parallel relationship to separator plates 12. Interposed in abutting relationship between one face of baflle 52 and one of the two separator plates 12 defining passages 22, is a rectangular corrugated slotted fin packing section 54 having the crests and troughs thereof extending parallel to the aforementioned second axis for conducting fluid from one of sections 46 to the other of sections 46 in a path parallel to said second axis. Interposed in abutting relationship between the other face of batfle plate 52 and the other separating plate 12 defining passage 22, is a second rectangular corrugated slotted fin packing section 56 having the crests and troughs thereof extending parallel to a third axis extending normal to the aforementioned first and second axes. It will be understood that baflie 52 greatly enhances the structural continuity of the heat exchanger core in the area of fin packings 54 and 56 which have corrugations extending normal to each other and thus greatly enhance the ability of the core to withstand pressure loads. Fin sections 54 and 56 are formed by corrugating a metallic sheet having slotted perforations 58 therein. The slots extend normal to the crests and troughs of the section. Preferably, the corrugations of sections 54 and 56 are more widely spaced than the corrugations of sections 46 to provide a low pressure drop. When assembled, one edge of section 56 abuts a closing bar 14 on one side of the passage while the opposite edge is received in a notch 60 of the closing bar 14 designated as 14a on the other side of passage 22. As will be seen, notch 60 forms a bleed opening or port intermediate the ends of passage 22. Baffle plate 52 is provided with flanges 62 which extend parallel to the said third axis across the width of passage 22 which enclose fin section 56 on the upstream and downstream edges thereof. Fin section 56 is thus isolated from the other portion of passage 22 by baflle 52.

To provide fluid communication between fin section 56 and the other portion of the passage 22 there is provided a plurality of rows 63 of through-going circular apertures 64 in bafile plate 52 which rows extend in a direction parallel to said third axis. Each of apertures 64 is so spaced as to be in registry with the loop or trough portions of both corrugated fin sections 54 and 56 thereby permitting fluid communication between the trough portions of fin section 54 and the trough portions of fin section 56.

Apertures 64 arranged in this manner do not detract appreciably from the strengthening effect of baflle 52, as

the apertures do not coincide with the crests of the corrugations of sections 54 and 56. Apertures 64 in each row 63yare made progressively smaller toward header 28 for reasons hereafter explained. As an alternative a tapered slot may be substituted for each row 63 of apertures. Such slots if desired may be angled obliquely from the corrugations of fin sections 54 and 56 thereby avoiding the need of placing the slots in registry with the trough portions of one of the sections 54 and 56.

The elements of the heat exchanger thus far described may be furnace or bath brazed as desired.

During operation of the heat exchanger a first heat exchange fluid enters header 18 (see FIG. 5) and is distributed thereby to each of the passages 16 through the triangular fin sections 34 disposed adjacent header 18 from whence the fluid is distributed across the width of each passage 16 via the trapezoidal fin section 32 disposed adjacent header 18. After being so distributed the fluid passes through fin section 30 to the trapezoidal fin section 32 disposed adjacent header 20 from whence it is conducted via the triangular fin section 34 disposed adjacent header 20 into header 20.

A second heat exchange fluid enters header 24 (see FIG. 4) and is distributed thereby to each of the passages 22 through the triangular fin section 50 disposed adjacent header 24 from whence the fluid is uniformly distributed across the width of each passage 22 via the trapezoidal fin section 48 disposed adjacent header 24. The second heat exchange fluid passes along the troughs of the fin section 46 disposed adjacent header 24 whereupon encountering the upstream flange 62 of bafile plate 52 the fluid is channeled into fin section 54. A portion of the fluid passes on through fin section 54 along the troughs thereof to the fin section 46 disposed adjacent header 26 from whence it is collected by the trapezoidal fin section 48 disposed adjacent header 26 and delivered to header 26 via the triangular fin section 50 disposed adjacent header 26.

A portion of the fluid passing in the troughs of fin section 54 is conducted through apertures 64 into the troughs of fin section 56. Slots 58 in section 54 permit this fluid to be collected from all the troughs of section 54 while slots 58 in fin section 56 provide for distribution of this fluid to all the troughs of fin section 56. The fluid in the troughs of fin section 56 is conducted toward the notch 60 in parallel relation to said third axis where said fluid emerges from the heat exchanger core and is collected by header 28 which overlies notches 60. It will be appreciated that the portion of fin section 56 adjacent notch 60 will necessarily be at a lower pressure than those portions more remote from notch 60. So that the bleed header conducts the fluid uniformly from the full width of each passage, the apertures 64 in each row 63 are made progressively smaller toward header 28 to provide a greater flow resistance where the pressure differential is greater.

The relative height of fin sections 54 and 56 may be selected to accommodate the relative proportions of, that portion of the fluid to be conducted entirely through passage 22, and that portion of the fluid to be withdrawn through header 28.

Although I have described in detail the preferred embodiment of my invention, I contemplate that many changes may be made without departing from the scope or spirit of my invention, and I desire to be limited only by the claims.

I claim:

1. A plate type brazed heat exchanger comprising a plurality of separator plates of generally similar configuration spaced in superposed substantially parallel relationship along a first axis; means sealingly connecting adjacent separatory plates along the margins thereof thereby defining fluid passages between said separator plates; means for conducting heat exchange fluid from one end to the other end of each of said passages in a direction generally parallel to a second axis extending parallel to said separator plates; a baffle plate disposed in one of said passages intermediate the ends thereof interposed in spaced substantially parallel relationship to said separator plates that define said one passage; a first heat exchange fin packing member disposed in said one passage at one face of said bafile plate and oriented to conduct heat exchange fluid in a direction generally parallel to said second axis; a second heat exchange fin packing member disposed in said one passage at the other face of said baffie plate oriented to conduct heat exchange fluid in a direction generally parallel to a third axis extending perpendicular to said first axis and transverse to said second axis; a third heat exchange fin packing member disposed in said one passage downstream of said baffle plate and having fins extending from one separator plate to the other one of said separator plates defining said one passage; and a port extending through said sealing means adjacent to and communicating with said second heat exchange fin member.

2. The apparatus of claim 1 wherein said balfie plate is porous.

3. The apparatus of claim 2 wherein the porosity of said baflle plate decreases in a direction parallel to said third axis toward said port.

4. The apparatus of claim 3 wherein the pores in said bafile plate include rows of apertures which rows extend axially with respect to said third axis.

5. The apparatus as defined by claim 1 wherein said second heat exchange fin packing member includes a corrugated sheet having the crests and troughs thereof extending parallel to said third axis.

6. The apparatus as defined by claim 5 wherein said corrugated sheet is perforated.

7. The apparatus as defined by claim 5 wherein said baflie plate includes a plurality of rows of apertures extending axially with respect to said third axis and spaced in registry with the trough portions of said second heat exchange fin packing member.

8. The apparatus of claim 1 wherein said first heat exchange fin packing member includes a corrugated sheet having the crests and troughs thereof extending parallel to said second axis.

9. The apparatus as defined by claim 8 wherein the corrugated sheet of said first heat exchange fin packing member is perforated.

10. The apparatus of claim 1 wherein said baffle plate has a pair of flanges each extending to said separator plate disposed adjacent said second heat exchange fin packing member and defining said one passage.

11. The apparatus of claim 10 wherein said sealing means includes an elongated member provided with an elongated notch in registry with one edge of said second heat exchange fin packing member thereby defining a port thereto.

12. The apparatus of claim 1 wherein said first heat exchange fin packing member is contiguous with said baffle plate and one of said separator plates defining said one passage and said second heat exchange fin packing member is contiguous with said bafile plate and the other of said separator plates defining said one passage.

13. The apparatus of claim 1 further including a fourth heat exchange fin member disposed in said one passage upstream of said bafile plate having fins extending from one separator plate to the other of the separator plates defining said passage.

14. The apparatus of claim 1 wherein said third heat exchange fin packing and one of said first and second heat exchange fin packings each are comprised of a corrugated sheet and the corrugations of said one fin packing are more widely spaced than the corrugations of said third fin packing.

References Cited UNITED STATES PATENTS 2,703,700 3/1955 Simpelaar -166 3,266,568 8/1966 Butt et al. 165--166 3,282,334 11/1966 Stahlheber 165166 ROBERT A. OLEARY, Primary Examiner.

C. SUKALO, Assistant Examiner. 

1. A PLATE TYPE BRAZED HEAT EXCHANGER COMPRISING A PLURALITY OF SEPARATOR PLATES OF GENERALLY SIMILAR CONFIGURATION SPACED IN SUPERPOSED SUBSTANTIALLY PARALLEL RELATIONSHIP ALONG A FIRST AXIS; MEANS SEALINGLY CONNECTING ADJACENT SEPARATORY PLATES ALONG THE MARGINS THEREOF THEREBY DEFINING FLUID PASSAGES BETWEEN SAID SEPARATOR PLATES; MEANS FOR CONDUCTING HEAT EXCHANGE FLUID FROM ONE END TO THE OTHER END OF EACH OF SAID PASSAGES IN A DIRECTION GENERALLY PARALLEL TO A SECOND AXIS EXTENDING PARALLEL TO SAID SEPARATOR PLATES; A BAFFLE PLATE DISPOSED IN ONE OF SAID PASSAGES INTERMEDIATE THE ENDS THEREOF INTERPOSED IN SPACED SUBSTANTIALLY PARALLEL RELATIONSHIP TO SAID SEPARATOR PLATES THAT DEFINE SAID ONE PASSAGE; A FIRST HEAT EXCHANGE FIN PACKING MEMBER DISPOSED IN SAID ONE PASSAGE AT ONE FACE OF SAID BAFFLE PLATE AND ORIENTED TO CONDUCT HEAT EXCHANGE FLUID IN A DIRECTION GENERALLY PARALLEL TO SAID SECOND AXIS; A SECOND HEAT EXCHANGE FIN PACKING MEMBER DISPOSED IN SAID ONE PASSAGE AT THE OTHER FACE OF SAID BAFFLE PLATE ORIENTED TO CONDUCT HEAT EXCHANGE FLUID IN A DIRECTION GENERALLY PARALLEL TO A THIRD AXIS EXTENDING PERPENDICULAR TO SAID FIRST AXIS AND TRANSVERSE TO SAID SECOND AXIS; A THIRD HEAT EXCHANGE FIN PACKING MEMBER DISPOSED IN SAID ONE PASSAGE DOWNSTREAM OF SAID BAFFLE PLATE AND HAVING FINS EXTENDING FROM ONE SEPARATOR PLATE TO THE OTHER ONE OF SAID SEPARATOR PLATES DEFINING SAID ONE PASSAGE; AND A PORT EXTENDING THROUGH SAID SEALING MEANS ADJACENT TO AND COMMUNICATING WITH SAID SECOND HEAT EXCHANGE FIN MEMBER. 